// Copyright 2011 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
// -----------------------------------------------------------------------------
//
// Cost tables for level and modes
//
// Author: Skal (pascal.massimino@gmail.com)

#include "src/enc/cost_enc.h"

#include <stdlib.h>

#include "src/dec/common_dec.h"
#include "src/dsp/dsp.h"
#include "src/enc/vp8i_enc.h"
#include "src/webp/types.h"

//------------------------------------------------------------------------------
// Level cost tables

// For each given level, the following table gives the pattern of contexts to
// use for coding it (in [][0]) as well as the bit value to use for each
// context (in [][1]).
static const uint16_t VP8LevelCodes[MAX_VARIABLE_LEVEL][2] = {
    {0x001, 0x000}, {0x007, 0x001}, {0x00f, 0x005}, {0x00f, 0x00d},
    {0x033, 0x003}, {0x033, 0x003}, {0x033, 0x023}, {0x033, 0x023},
    {0x033, 0x023}, {0x033, 0x023}, {0x0d3, 0x013}, {0x0d3, 0x013},
    {0x0d3, 0x013}, {0x0d3, 0x013}, {0x0d3, 0x013}, {0x0d3, 0x013},
    {0x0d3, 0x013}, {0x0d3, 0x013}, {0x0d3, 0x093}, {0x0d3, 0x093},
    {0x0d3, 0x093}, {0x0d3, 0x093}, {0x0d3, 0x093}, {0x0d3, 0x093},
    {0x0d3, 0x093}, {0x0d3, 0x093}, {0x0d3, 0x093}, {0x0d3, 0x093},
    {0x0d3, 0x093}, {0x0d3, 0x093}, {0x0d3, 0x093}, {0x0d3, 0x093},
    {0x0d3, 0x093}, {0x0d3, 0x093}, {0x153, 0x053}, {0x153, 0x053},
    {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053},
    {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053},
    {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053},
    {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053},
    {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053},
    {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053},
    {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x053},
    {0x153, 0x053}, {0x153, 0x053}, {0x153, 0x153}};

static int VariableLevelCost(int level, const uint8_t probas[NUM_PROBAS]) {
  int pattern = VP8LevelCodes[level - 1][0];
  int bits = VP8LevelCodes[level - 1][1];
  int cost = 0;
  int i;
  for (i = 2; pattern; ++i) {
    if (pattern & 1) {
      cost += VP8BitCost(bits & 1, probas[i]);
    }
    bits >>= 1;
    pattern >>= 1;
  }
  return cost;
}

//------------------------------------------------------------------------------
// Pre-calc level costs once for all

void VP8CalculateLevelCosts(VP8EncProba* const proba) {
  int ctype, band, ctx;

  if (!proba->dirty) return;  // nothing to do.

  for (ctype = 0; ctype < NUM_TYPES; ++ctype) {
    int n;
    for (band = 0; band < NUM_BANDS; ++band) {
      for (ctx = 0; ctx < NUM_CTX; ++ctx) {
        const uint8_t* const p = proba->coeffs[ctype][band][ctx];
        uint16_t* const table = proba->level_cost[ctype][band][ctx];
        const int cost0 = (ctx > 0) ? VP8BitCost(1, p[0]) : 0;
        const int cost_base = VP8BitCost(1, p[1]) + cost0;
        int v;
        table[0] = VP8BitCost(0, p[1]) + cost0;
        for (v = 1; v <= MAX_VARIABLE_LEVEL; ++v) {
          table[v] = cost_base + VariableLevelCost(v, p);
        }
        // Starting at level 67 and up, the variable part of the cost is
        // actually constant.
      }
    }
    for (n = 0; n < 16; ++n) {  // replicate bands. We don't need to sentinel.
      for (ctx = 0; ctx < NUM_CTX; ++ctx) {
        proba->remapped_costs[ctype][n][ctx] =
            proba->level_cost[ctype][VP8EncBands[n]][ctx];
      }
    }
  }
  proba->dirty = 0;
}

//------------------------------------------------------------------------------
// Mode cost tables.

// These are the fixed probabilities (in the coding trees) turned into bit-cost
// by calling VP8BitCost().
const uint16_t VP8FixedCostsUV[4] = {302, 984, 439, 642};
// note: these values include the fixed VP8BitCost(1, 145) mode selection cost.
const uint16_t VP8FixedCostsI16[4] = {663, 919, 872, 919};
const uint16_t VP8FixedCostsI4[NUM_BMODES][NUM_BMODES][NUM_BMODES] = {
    {{40, 1151, 1723, 1874, 2103, 2019, 1628, 1777, 2226, 2137},
     {192, 469, 1296, 1308, 1849, 1794, 1781, 1703, 1713, 1522},
     {142, 910, 762, 1684, 1849, 1576, 1460, 1305, 1801, 1657},
     {559, 641, 1370, 421, 1182, 1569, 1612, 1725, 863, 1007},
     {299, 1059, 1256, 1108, 636, 1068, 1581, 1883, 869, 1142},
     {277, 1111, 707, 1362, 1089, 672, 1603, 1541, 1545, 1291},
     {214, 781, 1609, 1303, 1632, 2229, 726, 1560, 1713, 918},
     {152, 1037, 1046, 1759, 1983, 2174, 1358, 742, 1740, 1390},
     {512, 1046, 1420, 753, 752, 1297, 1486, 1613, 460, 1207},
     {424, 827, 1362, 719, 1462, 1202, 1199, 1476, 1199, 538}},
    {{240, 402, 1134, 1491, 1659, 1505, 1517, 1555, 1979, 2099},
     {467, 242, 960, 1232, 1714, 1620, 1834, 1570, 1676, 1391},
     {500, 455, 463, 1507, 1699, 1282, 1564, 982, 2114, 2114},
     {672, 643, 1372, 331, 1589, 1667, 1453, 1938, 996, 876},
     {458, 783, 1037, 911, 738, 968, 1165, 1518, 859, 1033},
     {504, 815, 504, 1139, 1219, 719, 1506, 1085, 1268, 1268},
     {333, 630, 1445, 1239, 1883, 3672, 799, 1548, 1865, 598},
     {399, 644, 746, 1342, 1856, 1350, 1493, 613, 1855, 1015},
     {622, 749, 1205, 608, 1066, 1408, 1290, 1406, 546, 971},
     {500, 753, 1041, 668, 1230, 1617, 1297, 1425, 1383, 523}},
    {{394, 553, 523, 1502, 1536, 981, 1608, 1142, 1666, 2181},
     {655, 430, 375, 1411, 1861, 1220, 1677, 1135, 1978, 1553},
     {690, 640, 245, 1954, 2070, 1194, 1528, 982, 1972, 2232},
     {559, 834, 741, 867, 1131, 980, 1225, 852, 1092, 784},
     {690, 875, 516, 959, 673, 894, 1056, 1190, 1528, 1126},
     {740, 951, 384, 1277, 1177, 492, 1579, 1155, 1846, 1513},
     {323, 775, 1062, 1776, 3062, 1274, 813, 1188, 1372, 655},
     {488, 971, 484, 1767, 1515, 1775, 1115, 503, 1539, 1461},
     {740, 1006, 998, 709, 851, 1230, 1337, 788, 741, 721},
     {522, 1073, 573, 1045, 1346, 887, 1046, 1146, 1203, 697}},
    {{105, 864, 1442, 1009, 1934, 1840, 1519, 1920, 1673, 1579},
     {534, 305, 1193, 683, 1388, 2164, 1802, 1894, 1264, 1170},
     {305, 518, 877, 1108, 1426, 3215, 1425, 1064, 1320, 1242},
     {683, 732, 1927, 257, 1493, 2048, 1858, 1552, 1055, 947},
     {394, 814, 1024, 660, 959, 1556, 1282, 1289, 893, 1047},
     {528, 615, 996, 940, 1201, 635, 1094, 2515, 803, 1358},
     {347, 614, 1609, 1187, 3133, 1345, 1007, 1339, 1017, 667},
     {218, 740, 878, 1605, 3650, 3650, 1345, 758, 1357, 1617},
     {672, 750, 1541, 558, 1257, 1599, 1870, 2135, 402, 1087},
     {592, 684, 1161, 430, 1092, 1497, 1475, 1489, 1095, 822}},
    {{228, 1056, 1059, 1368, 752, 982, 1512, 1518, 987, 1782},
     {494, 514, 818, 942, 965, 892, 1610, 1356, 1048, 1363},
     {512, 648, 591, 1042, 761, 991, 1196, 1454, 1309, 1463},
     {683, 749, 1043, 676, 841, 1396, 1133, 1138, 654, 939},
     {622, 1101, 1126, 994, 361, 1077, 1203, 1318, 877, 1219},
     {631, 1068, 857, 1650, 651, 477, 1650, 1419, 828, 1170},
     {555, 727, 1068, 1335, 3127, 1339, 820, 1331, 1077, 429},
     {504, 879, 624, 1398, 889, 889, 1392, 808, 891, 1406},
     {683, 1602, 1289, 977, 578, 983, 1280, 1708, 406, 1122},
     {399, 865, 1433, 1070, 1072, 764, 968, 1477, 1223, 678}},
    {{333, 760, 935, 1638, 1010, 529, 1646, 1410, 1472, 2219},
     {512, 494, 750, 1160, 1215, 610, 1870, 1868, 1628, 1169},
     {572, 646, 492, 1934, 1208, 603, 1580, 1099, 1398, 1995},
     {786, 789, 942, 581, 1018, 951, 1599, 1207, 731, 768},
     {690, 1015, 672, 1078, 582, 504, 1693, 1438, 1108, 2897},
     {768, 1267, 571, 2005, 1243, 244, 2881, 1380, 1786, 1453},
     {452, 899, 1293, 903, 1311, 3100, 465, 1311, 1319, 813},
     {394, 927, 942, 1103, 1358, 1104, 946, 593, 1363, 1109},
     {559, 1005, 1007, 1016, 658, 1173, 1021, 1164, 623, 1028},
     {564, 796, 632, 1005, 1014, 863, 2316, 1268, 938, 764}},
    {{266, 606, 1098, 1228, 1497, 1243, 948, 1030, 1734, 1461},
     {366, 585, 901, 1060, 1407, 1247, 876, 1134, 1620, 1054},
     {452, 565, 542, 1729, 1479, 1479, 1016, 886, 2938, 1150},
     {555, 1088, 1533, 950, 1354, 895, 834, 1019, 1021, 496},
     {704, 815, 1193, 971, 973, 640, 1217, 2214, 832, 578},
     {672, 1245, 579, 871, 875, 774, 872, 1273, 1027, 949},
     {296, 1134, 2050, 1784, 1636, 3425, 442, 1550, 2076, 722},
     {342, 982, 1259, 1846, 1848, 1848, 622, 568, 1847, 1052},
     {555, 1064, 1304, 828, 746, 1343, 1075, 1329, 1078, 494},
     {288, 1167, 1285, 1174, 1639, 1639, 833, 2254, 1304, 509}},
    {{342, 719, 767, 1866, 1757, 1270, 1246, 550, 1746, 2151},
     {483, 653, 694, 1509, 1459, 1410, 1218, 507, 1914, 1266},
     {488, 757, 447, 2979, 1813, 1268, 1654, 539, 1849, 2109},
     {522, 1097, 1085, 851, 1365, 1111, 851, 901, 961, 605},
     {709, 716, 841, 728, 736, 945, 941, 862, 2845, 1057},
     {512, 1323, 500, 1336, 1083, 681, 1342, 717, 1604, 1350},
     {452, 1155, 1372, 1900, 1501, 3290, 311, 944, 1919, 922},
     {403, 1520, 977, 2132, 1733, 3522, 1076, 276, 3335, 1547},
     {559, 1374, 1101, 615, 673, 2462, 974, 795, 984, 984},
     {547, 1122, 1062, 812, 1410, 951, 1140, 622, 1268, 651}},
    {{165, 982, 1235, 938, 1334, 1366, 1659, 1578, 964, 1612},
     {592, 422, 925, 847, 1139, 1112, 1387, 2036, 861, 1041},
     {403, 837, 732, 770, 941, 1658, 1250, 809, 1407, 1407},
     {896, 874, 1071, 381, 1568, 1722, 1437, 2192, 480, 1035},
     {640, 1098, 1012, 1032, 684, 1382, 1581, 2106, 416, 865},
     {559, 1005, 819, 914, 710, 770, 1418, 920, 838, 1435},
     {415, 1258, 1245, 870, 1278, 3067, 770, 1021, 1287, 522},
     {406, 990, 601, 1009, 1265, 1265, 1267, 759, 1017, 1277},
     {968, 1182, 1329, 788, 1032, 1292, 1705, 1714, 203, 1403},
     {732, 877, 1279, 471, 901, 1161, 1545, 1294, 755, 755}},
    {{111, 931, 1378, 1185, 1933, 1648, 1148, 1714, 1873, 1307},
     {406, 414, 1030, 1023, 1910, 1404, 1313, 1647, 1509, 793},
     {342, 640, 575, 1088, 1241, 1349, 1161, 1350, 1756, 1502},
     {559, 766, 1185, 357, 1682, 1428, 1329, 1897, 1219, 802},
     {473, 909, 1164, 771, 719, 2508, 1427, 1432, 722, 782},
     {342, 892, 785, 1145, 1150, 794, 1296, 1550, 973, 1057},
     {208, 1036, 1326, 1343, 1606, 3395, 815, 1455, 1618, 712},
     {228, 928, 890, 1046, 3499, 1711, 994, 829, 1720, 1318},
     {768, 724, 1058, 636, 991, 1075, 1319, 1324, 616, 825},
     {305, 1167, 1358, 899, 1587, 1587, 987, 1988, 1332, 501}}};

//------------------------------------------------------------------------------
// helper functions for residuals struct VP8Residual.

void VP8InitResidual(int first, int coeff_type, VP8Encoder* const enc,
                     VP8Residual* const res) {
  res->coeff_type = coeff_type;
  res->prob = enc->proba.coeffs[coeff_type];
  res->stats = enc->proba.stats[coeff_type];
  res->costs = enc->proba.remapped_costs[coeff_type];
  res->first = first;
}

//------------------------------------------------------------------------------
// Mode costs

int VP8GetCostLuma4(VP8EncIterator* const it, const int16_t levels[16]) {
  const int x = (it->i4 & 3), y = (it->i4 >> 2);
  VP8Residual res;
  VP8Encoder* const enc = it->enc;
  int R = 0;
  int ctx;

  VP8InitResidual(0, 3, enc, &res);
  ctx = it->top_nz[x] + it->left_nz[y];
  VP8SetResidualCoeffs(levels, &res);
  R += VP8GetResidualCost(ctx, &res);
  return R;
}

int VP8GetCostLuma16(VP8EncIterator* const it, const VP8ModeScore* const rd) {
  VP8Residual res;
  VP8Encoder* const enc = it->enc;
  int x, y;
  int R = 0;

  VP8IteratorNzToBytes(it);  // re-import the non-zero context

  // DC
  VP8InitResidual(0, 1, enc, &res);
  VP8SetResidualCoeffs(rd->y_dc_levels, &res);
  R += VP8GetResidualCost(it->top_nz[8] + it->left_nz[8], &res);

  // AC
  VP8InitResidual(1, 0, enc, &res);
  for (y = 0; y < 4; ++y) {
    for (x = 0; x < 4; ++x) {
      const int ctx = it->top_nz[x] + it->left_nz[y];
      VP8SetResidualCoeffs(rd->y_ac_levels[x + y * 4], &res);
      R += VP8GetResidualCost(ctx, &res);
      it->top_nz[x] = it->left_nz[y] = (res.last >= 0);
    }
  }
  return R;
}

int VP8GetCostUV(VP8EncIterator* const it, const VP8ModeScore* const rd) {
  VP8Residual res;
  VP8Encoder* const enc = it->enc;
  int ch, x, y;
  int R = 0;

  VP8IteratorNzToBytes(it);  // re-import the non-zero context

  VP8InitResidual(0, 2, enc, &res);
  for (ch = 0; ch <= 2; ch += 2) {
    for (y = 0; y < 2; ++y) {
      for (x = 0; x < 2; ++x) {
        const int ctx = it->top_nz[4 + ch + x] + it->left_nz[4 + ch + y];
        VP8SetResidualCoeffs(rd->uv_levels[ch * 2 + x + y * 2], &res);
        R += VP8GetResidualCost(ctx, &res);
        it->top_nz[4 + ch + x] = it->left_nz[4 + ch + y] = (res.last >= 0);
      }
    }
  }
  return R;
}

//------------------------------------------------------------------------------
// Recording of token probabilities.

// We keep the table-free variant around for reference, in case.
#define USE_LEVEL_CODE_TABLE

// Simulate block coding, but only record statistics.
// Note: no need to record the fixed probas.
int VP8RecordCoeffs(int ctx, const VP8Residual* const res) {
  int n = res->first;
  // should be stats[VP8EncBands[n]], but it's equivalent for n=0 or 1
  proba_t* s = res->stats[n][ctx];
  if (res->last < 0) {
    VP8RecordStats(0, s + 0);
    return 0;
  }
  while (n <= res->last) {
    int v;
    VP8RecordStats(1, s + 0);  // order of record doesn't matter
    while ((v = res->coeffs[n++]) == 0) {
      VP8RecordStats(0, s + 1);
      s = res->stats[VP8EncBands[n]][0];
    }
    VP8RecordStats(1, s + 1);
    if (!VP8RecordStats(2u < (unsigned int)(v + 1), s + 2)) {  // v = -1 or 1
      s = res->stats[VP8EncBands[n]][1];
    } else {
      v = abs(v);
#if !defined(USE_LEVEL_CODE_TABLE)
      if (!VP8RecordStats(v > 4, s + 3)) {
        if (VP8RecordStats(v != 2, s + 4)) VP8RecordStats(v == 4, s + 5);
      } else if (!VP8RecordStats(v > 10, s + 6)) {
        VP8RecordStats(v > 6, s + 7);
      } else if (!VP8RecordStats((v >= 3 + (8 << 2)), s + 8)) {
        VP8RecordStats((v >= 3 + (8 << 1)), s + 9);
      } else {
        VP8RecordStats((v >= 3 + (8 << 3)), s + 10);
      }
#else
      if (v > MAX_VARIABLE_LEVEL) {
        v = MAX_VARIABLE_LEVEL;
      }

      {
        const int bits = VP8LevelCodes[v - 1][1];
        int pattern = VP8LevelCodes[v - 1][0];
        int i;
        for (i = 0; (pattern >>= 1) != 0; ++i) {
          const int mask = 2 << i;
          if (pattern & 1) VP8RecordStats(!!(bits & mask), s + 3 + i);
        }
      }
#endif
      s = res->stats[VP8EncBands[n]][2];
    }
  }
  if (n < 16) VP8RecordStats(0, s + 0);
  return 1;
}

//------------------------------------------------------------------------------
